Thursday 30 August 2012 03.10 EDT
First published on Thursday 30 August 2012 03.10 EDT

The Republican vice-presidential candidate, Paul Ryan, won a series of standing ovations during a primetime keynote address to the party's national convention in which he set out the case for small government and prepared the ground for Mitt Romney's big speech on Thursday night.

Although Ryan failed to generate the same level of excitement as Sarah Palin at the 2008 convention, he did enough in Tampa to fire up what had been a listless event, dogged by bad weather and lack of enthusiasm over Romney.

He set out an alternative economic strategy to the Obama adminstration, promising to create millions of new jobs over the next four years and won loud applause for saying a Romney administration would protect Medicare.

Ryan secured some of the loudest bursts of applause for his attacks on Obama. One image that resonated with the tens of thousands crowded into the convention centre was when Ryan spoke about students. "College graduates should not have to live out their 20s in their childhood bedrooms, staring up at fading Obama posters and wondering when they can move out and get going with life," he said.

"Everyone who feels stuck in the Obama economy is right to focus on the here and now. And I hope you understand this too, if you're feeling left out or passed by: you have not failed, your leaders have failed you."

The immediate reaction from senior Republicans, however, was positive. "He did all he had to do. He introduced himself personally to the American people," said the former House Speaker and one-time Romney rival Newt Gingrich.

Gingrich told the Guardian: "Paul Ryan knows more than Joe Biden has remembered or confused." Addressing concern about his lack of experience, Gingrich pointed out that Ryan, 42, is only four years younger than Obama was when elected to the presidency and already has much more political experience than the then Democratic candidate.

Ryan's was a measured speech that began nervously but got stronger as it progressed. He had two difficult acts to follow after former secretary of state Condoleezza Rice and the governor of New Mexico, Susana Martinez, delivered powerful addresses.

He couched his speech in moral terms. "We have responsibilities, one to another – we do not each face the world alone. And the greatest of all responsibilities is that of the strong to protect the weak. The truest measure of any society is how it treats those who cannot defend or care for themselves," he said.

He added: "Our rights come from nature and God, not from government."

The focus now shifts to Romney, who now has to deliver the speech of his life to the convention, one that could determine whether he or Obama will be the next president. He has to win over not only conservatives at the convention, to ensure they turn out as volunteers and on election day, but more importantly an estimated television audience of more than 30 million.

The convention in the early evening had been flat, lacking in energy, with delegates milling around, not listening to the speakers.

Rice fired them up, accusing Obama of leading from the back in foreign policy. She brought the convention to its feet again towards the end of her speech when she spoke about how a girl who had been banned under the Jim Crow laws from eating a hamburger in her local Woolworth's store in her hometown, Alabama, and rose to become secretary of state.

There was a brief protest when a small group of women unfurled a banner saying "Vagina", making their point about Republican policies on abortion and other issues related to women. To shouts of "USA, USA" from the delegates they left the hall.

The divisions and tensions in the Republican party were exposed again when hundreds of supporters of the libertarian Texas Congressman Ron Paul – who accumulated a lot of delegates during his bid for the presidential nomination – walked out over rules changes they see as limiting grassroots rights.